The present invention provides digital watermarks through multiple channels. The channels can include, e.g., visible, ultraviolet and infrared channels. The non-visible channels can be selected to fluoresce either in the visible or IR/UV spectrums upon the appropriate illumination in the infrared or ultraviolet spectrums. The watermarks in the various multiple channels can cooperate to facilitate watermark detection or to authenticate an object in which the watermarks are embedded. In other implementations the multiple watermarks include so-called orientation components. A relative relationship between the orientation components is used to convey data.